Additive for heating asphalt

ABSTRACT

The invention provides an additive for heated asphalt that can further improve a peeling prevention effect between asphalt and aggregates. The invention relates to an additive which is added to heated asphalt containing a particular gallic acid ester and so on.

FIELD OF THE INVENTION

The present invention relates to an additive for heated asphalt used inpaving roads and so on.

BACKGROUND OF THE INVENTION

Petroleum asphalt is used as a paving material, a roofing material, awaterproof material, and so on. Among these usages, demand for thepaving material is the largest. In paving roads with heated asphalt,aggregates and asphalt are mixed and applied under heat. However, sincenonpolar hydrophobic asphalt does not adhere sufficiently to hydrophilicaggregates, there is a potential problem in that asphalt peels from theaggregates through the interventional action of rainfall and groundwater.

Thus, an improvement in the adhesiveness between the asphalt and theaggregates is a very important item for improving performance of thepaved roads with heated asphalt; accordingly, many methods have beendevised so far to improve the same.

For example, in JP-A No. 2001-2928, as a countermeasure for this, higheraliphatic polyalkylene polyamine and a salt of a modified polyolefinresin having a carboxyl group are used. However, although the adhesiveproperty immediate after the addition to the heated asphalt can beimproved, there is a problem in that the peeling prevention effectdecreases after 4 to 7 days when preserved at a high temperature.

Furthermore, in JP-A No. 60-188462, it is described that a specificacidic organic phosphorous compound is effective in solving the problemmentioned above. However, though the adhesive property and the peelingeffect are improved compared with other additives so far proposed, thereis still room for improvement in the immediate result demanded in themarket.

Recently there is a concern about the deterioration in qualities ofasphalt and the aggregates. From the viewpoint of the effectiveutilization of resources, on the other hand, a recycling method of wastematerials of pavement is proposed. However, in this case, asdeteriorated asphalt is used, strong adhesion cannot be anticipated.

As just described, there is a tendency for increased demand for animproved asphalt for paving materials that uses the heated asphalt andthe aggregates. However, a method that can solve the problems mentionedabove and the performances demanded in market has not been developedyet.

Furthermore, in JP-A No. 9-157530, asphalt emulsion containing a gallicacid and/or gallic acid derivative is described. However, it is atechnology relating to an asphalt emulsion system and has no relationwith a system that uses heated asphalt containing no water.

SUMMARY OF THE INVENTION

The present invention relates to an additive for use in heated asphaltcontaining (I) and/or (II) below.(I) Compounds represented by formula (1) below.

In the formula, R represents a hydrocarbon group having 1 to 22 carbonatoms.(II) A compound represented by formula (2) and compounds represented byformula (3).

R—OH   (3)

Furthermore, the invention relates to a heated asphalt composition inwhich an additive according to the invention is blended with asphaltheated at a temperature of 100 to 300° C.

Still furthermore, the invention relates to a heated asphalt compositioncontaining the additive according to the invention and asphalt heated ata temperature of 100 to 300° C., the heated asphalt compositioncontaining the additive in the range of 0.005 to 3% by weight relativeto the asphalt.

Furthermore, the invention relates to a method of preventing asphaltfrom peeling, including adding the additive according to the inventionto asphalt, wherein the additive contains no water.

Still furthermore, the invention relates to a method of preventingasphalt from peeling, including adding the additive according to theinvention by 0.005 to 3% by weight to asphalt heated at a temperature of100 to 300° C.

Furthermore, the invention relates to a method of manufacturing a heatedasphalt composition, including adding the additive according to theinvention by 0.005 to 3% by weight to asphalt heated at a temperature of100 to 300° C.

Still furthermore, the invention relates to a heated asphalt compositionthat contains at least one compound selected from compounds (I)represented by formula (1) and compounds (II) represented by formulas(2) and (3), that is, compounds (I) and/or (II) and heated asphalt. Thecompounds (II) contain compounds according to formulas (2) and (3).Furthermore, the invention provides a method of preventing asphalt frompeeling from aggregates, including adding the compounds to heatedasphalt and then use of the compound as a heated asphalt additive.

DETAILED DESCRIPTION OF THE INVENTION

The compounds according to formula (1) that are used in an additive foruse in heated asphalt of the invention each have an —OH groupsubstituted in the benzene ring. In the invention, the compoundsrepresented by formula (1) can be used separately or in combinations oftwo or more kinds.

Furthermore, each of the compounds represented by formula (2) andformula (3) can be used together from separately prepared ones.

The R in formula (1) or (3) represents a saturated or unsaturated andbranched or straight chain hydrocarbon group having 1 to 22 carbonatoms, preferably having 5 to 20 carbon atoms, more preferably having 10to 20 carbon atoms, and even more preferably having 10 to 18 carbonatoms. Alternatively, it may be a hydrocarbon group having 8 to 22carbon atoms. Examples of such hydrocarbon groups include alkyl groupssuch as octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl,pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl,stearyl, lauryl, myristyl, isoamyl and isopropyl; and alkyl phenylgroups such as octyl phenyl, nonyl phenyl, decyl phenyl, dodecyl phenyl,tridecyl phenyl and tetradecyl phenyl. The R is preferably an alkylgroup having 1 to 22 carbon atoms or an alkenyl group having 2 to 22carbon atoms, or an alkyl phenyl group having 7 to 22 carbon atoms. Analkyl group having 5 to 20 carbon atoms is preferable, and a straightchain alkyl group having 10 to 18 carbon atoms is more preferable.

There is no restriction on the method of manufacturing a compoundrepresented by formula (1). However, a method of allowing reactingsaturated or unsaturated, and branched or straight chain alcohol oralkylphenol having 1 to 22 carbon atoms with gallic acid contained inhydrolysable tannin material under the presence of a strong acidcatalyst under a high temperature of 100° C. or more can be carried out.The examples of tannin material include condensed tannin such asnutgall, gall, smack, tare, valonia, chestnut, myrobalan, oak,Divi-Divi, and Algarobilla. The adequate examples of the strong acidinclude preferably sulfuric acid, hydrochloric acid or p-toluenesulfonic acid in the anhydrous form. Though it is possible tomanufacture without using a strong acid catalyst, it takes a longreaction time in that case.

The reason why the asphalt additive according to the invention thatcontains the compound represented by formula (1) develops theadhesiveness and the peeling prevention effect immediately after theaddition of the asphalt is not necessarily apparent. However, that the—OH group in the compound represented by formula (1) and the Si group ona surface of the aggregates generate a hydrogen bond is thought as thereason for this. Furthermore, since the compound represented by formula(1) is excellent in the mixability with the asphalt, it is thought thatthe bonding between the aggregates and asphalt becomes stronger. Stillfurthermore, when the compound represented by formula (2) and thecompound represented by formula (3) are used together, it is consideredthat the compound represented by formula (2) reacts with the compoundrepresented by formula (3) in the heated asphalt to form the compoundrepresented by formula (1), and thereby an effect is exhibited.

In addition, when the compound represented by formula (2) and thecompound represented by formula (3) are used together, a weight ratio of(2) to (3) is preferably 90/10 to 10/90, more preferably 70/30 to 30/70,and particularly preferably 60/40 to 40/60.

The additive according to the invention is blended with the asphaltpreferably in the range of 0.01 to 3% by weight relative to the asphalt,more preferably in the range of 0.02 to 2% by weight, and still morepreferably in the range of 0.05 to 1.5% by weight. When the additionamount is within this range, excellent adhesiveness between the asphaltand the aggregates as well as the peeling prevention effect can beexhibited.

There is no restriction on the method of adding the additive to theasphalt according to the invention; for example, a predetermined amountthereof has only to be added to asphalt heated and melted at 100 to 250°C. under agitation. Furthermore, since the additive according to theinvention is excellent in the solubility and the affinity to the asphaltand thus can be blended evenly enough owing to thermal convection orvibration during transportation, there is no need of agitation; however,when immediate effect is demanded, blending is preferably carried outunder agitation.

The heated asphalt additive according to the invention can be usedtogether with various kinds of aliphatic amines. These are used tofurther improve the initial stage wettability of the asphalt to theaggregates owing to the presence of a nitrogen atom in a molecule. Theexamples of aliphatic amines include higher aliphatic pblyamine typicalin tallow propylene diamine and derivatives thereof, and alkylol aminesuch as alkylhydroxyamine, monoethanolamine, diethanolamine andtriethanolamine.

The total content of the compound represented by formula (1) and/or thecompound represented by formula (2) and the compound represented byformula (3) contained in the additive according to the invention ispreferably in the range of 70 to 100% by weight, more preferably in therange of 80 to 100% by weight, and even more preferably in the range of85 to 100% by weight.

In addition, in the additive according to the invention, a ratio of thetotal amount of the compound represented by formula (1) and/or thecompound represented by formula (2) and the compound represented byformula (3) is preferably in the range of 0.005 to 3% by weight relativeto the asphalt, more preferably 0.01 to 2% by weight, and even morepreferably 0.03 to 1% by weight. Within this range, the peeling of theasphalt from the aggregates can be most effectively inhibited fromoccurring.

Furthermore, the additive according to the invention may include aslight amount of water in a range that does not deteriorate the effectof the invention. However, considering that the additive is blended withheated asphalt, the content of water is preferably 0.2% by weight orless, and more preferably 0.05% by weight or less. Particularlypreferably, it is used in a state that does not contain water.

When the additive according to the invention is blended with asphaltheated at a temperature of 100 to 300° C., a heated asphalt compositioncan be prepared.

Examples of asphalt which may be used in the invention include asphaltmanufactured by adding a softener to petroleum straight asphalt,semi-blown asphalt, cut-back asphalt, natural asphalt, petroleum tar,pitch or bituminous substance generated from solvent deasphalting so asto satisfy standards of asphalt for road pavement. Furthermore, reformedasphalt with increased consistency that is obtained by blending theasphalt with natural rubbers; synthetic rubbers such asstyrene-butadiene copolymer and chloroprene polymer; thermoplasticelastomers; homopolymers of ethylene, vinyl acetate, acrylic ester,methacrylic ester and styrene or copolymers thereof may be used. Thesecan be used heated at a temperature of 100 to 300° C., usually at atemperature of 160 to 250° C., and furthermore at a temperature 180 to220° C.

To the heated asphalt composition according to the invention, inaccordance with the respective objects, inorganic and organic fillerssuch as calcium carbonate, calcium hydroxide, cement and activatedcarbon, petroleum system softener such as petroleum resins and lowmolecular weight polyethylene, vegetable oil system softener such asoleic acid, various kinds of plasticizer and sulfur can be added.

The heated asphalt composition according to the invention can be used asa road paving material, a roofing material and a waterproof material.However, owing to the excellent peeling prevention performance, it isparticularly preferable for use as a paving material among theapplications.

The heated asphalt composition according to the invention can bepreferably mixed with the aggregates. A blending ratio of the heatedasphalt composition according to the invention to the aggregates ispreferably 1 to 15% by weight to 99 to 85% by weight. As the aggregates,broken stones, sand, fillers and so on can be used.

The additive for heated asphalt according to the invention makes theadherence of the heated asphalt and the aggregates stronger. As aresult, very excellent peeling prevention effect can be exhibited in theheated asphalt pavement.

EXAMPLE

According to a peel test of asphalt coating described in ASUFARUTO HOSOUYOUKOU (published by Japan Road Association), a test was carried out ofthe peelability between the asphalt and the aggregates according to amethod shown below.

(Method of Peel Test)

One hundred grams of each of grains, having grain sizes that passthrough a 13 mm mesh and are stopped by a 5 mm mesh, of aggregates(granite porphyry) from Takarazuka and aggregates (limestone) from Kuzuoare thoroughly washed, followed by drying in a 300 ml metal container.This is heated for an hour in a constant temperature drier that is keptat a temperature of 150° C. beforehand. On the other hand, after anasphalt composition is heated for a predetermined time period (2 hoursor 48 hours) in a constant temperature drier kept at a temperature of180° C., 5.5 g thereof is added to the aggregates. This is thoroughlyagitated for 2 or 3 minutes with a scoop so that the asphalt may coverthe surface of the broken stone completely. Subsequently, this is spreadon a glass plate and left for 1 hour to cool to room temperature and tocure. The covered aggregates is immersed for 60 minutes in warm water ina constant temperature water bath kept at 80° C. and cooled after 30minutes, followed by drying at room temperature. A state of the coveredaggregates is visually observed from above, and an area percentage ofpeeled asphalt composition coating is obtained with reference to an areaof asphalt composition coating at the time of test start. This isrepresented as the peeling rate.

EXAMPLE

A predetermined amount of a compound described in Table 1 was added toasphalt heated and melted at 180° C. followed by mixing at 180° C. for 1to 3 minutes by use of a turbine-like stirring blade to be homogeneous,and thereby an asphalt composition was obtained. The obtained asphaltcompositions were subjected to the peel test, and the results are shownin Table 1. TABLE 1 Addition Peeled area (%) amount* Granite porphyryLimestone Additive to heated asphalt (weight-%) 2 hours 48 hours 2 hours48 hours Product 1 Lauryl alcohol/gallic acid ester 0.2 0 <5 0 0 of the2 Mirystyl alcohol/gallic acid ester 0.2 0 <5 0 0 invention 3Dodecanol/gallic acid ester 0.2 0 5 0 <5 4 Stearyl alcohol/gallic acidester 0.03 0 5 0 <5 5 Stearyl alcohol/gallic acid ester 0.3 0 0 0 0 6Oleyl alcohol/gallic acid ester 0.3 <5 5 <5 <5 7 Cetyl alcohol/gallicacid ester 0.2 <5 5 <5 <5 8 Octyl alcohol/gallic acid ester 0.2 <10 10<10 10 9 Coconut oil alcohol/gallic acid ester 0.2 0 <5 0 <5 10 Nonylphenol/gallic acid ester 0.2 <5 5 <5 <5 11 Stearyl alcohol/gallic acidester 0.2 0 5 0 <5 Triethylene tetramine 0.05 12 Gallic acid 0.1 0 20 020 Stearyl alcohol 0.1 13 Stearyl alcohol/gallic acid ester 0.01 10 2010 20 14 Isoamyl alcohol/gallic acid ester 0.2 <5 <5 <5 <5 Comparative 1Nothing added — 60 80 40 70 product 2 Gallic acid 0.5 60 80 35 70 3Stearyl alcohol 0.5 60 60 40 50 4 Phosphoric acid 0.5 10 20 10 20 5Stearyl phosphate ester 0.1 20 60 20 30 6 Tallow alkyl propylene diamine0.5 10 30 10 20 7 Tallow alkyl propylene diamine 0.5 20 60 10 50Ethylene oxide three-mole adduct (average) 8 Oleylaminoethyl imidazoline0.5 10 60 10 40 9 1-aminoethyl-2- 0.5 20 70 10 50heptadecenylimidazoline-2 10 Oleilaminoethyl imidazoline 0.2 20 70 20 60*% by weight relative to asphalt

As is shown in Table 1, the asphalt composition containing the additivefor heated asphalt according to the invention shows strong adhesivenessto the aggregates either of the acidic rock or the basic rock and doesnot lose its effect even under heating for a long period. Furthermore,even when the time period of blending with the asphalt is made muchshorter, the adhesiveness and the peeling prevention effect are betterthan those of conventional ones, and thus it is apparent that animmediate effect is exhibited sufficiently.

In addition to the above, it is apparent that even when the additionamount of the inventive product is 0.01% by weight, the effect is thesame as or more than that of the case where a comparative product isadded by 0.5% by weight.

1. An additive for heated asphalt, comprising either one or both of (I) and (II) below: (I) a compound represented by formula (1) below

 wherein R represents a hydrocarbon group having 1 to 22 carbon atoms; (II) a compound represented by formula (2) and a compound represented by formula (3):

R—OH   (3)
 2. The heated asphalt composition that is formed by blending the additive according to claim 1 with asphalt heated at a temperature of 100 to 300° C.
 3. The heated asphalt composition comprising the additive according to claim 1 and asphalt heated at 100 to 300° C., wherein the additive is contained by −0.005 to 3% by weight relative to the asphalt.
 4. A method of preventing asphalt from peeling, comprising adding the additive according to claim 1 to the asphalt, the additive including no water.
 5. A method of preventing asphalt from peeling, comprising adding the additive according to claim 1 in an amount of 0.005 to 3% by weight of the asphalt heated at 100 to 300° C.
 6. A method of manufacturing a heated asphalt composition, comprising adding the additive according to claim 1 in an amount of 0.005 to 3% by weight of the asphalt heated at 100 to 300° C.
 7. The heated asphalt composition comprising at least one compound selected from the group of compounds (I) represented by formula (1) according to claim 1 and compounds (II) represented by formulas (2) and (3) according to claim 1, and heated asphalt.
 8. The method of adding the compound according to claim 7 to heated asphalt to inhibit the asphalt from peeling from an aggregate.
 9. Use of the compound according to claim 7 as an additive for heated asphalt. 